Control of 3x7 matrix converter with PWM three intervals modulation

Direct Power conversion from fixed AC voltage into variable AC voltage is gaining a significant attention, especially in case of multi-phases machines/generators; for such reason a new algorithm to control 3x7 matrix converter (MC) is developed in this paper, wherein the main aim is to control multi-phases induction motor/generator connected to the electrical grid with a novel converter (except matrix converter), for that the PWM three intervals modulation strategy is modified from the control of 3x3 MC to 3x7 MC; which is directly connected to the network through a three phase input in order to overcome the supplying problems, on the other side seven phases have been used as an output to benefit the advantages of the multi-phases machines. This paper intends in the first place to explain the 3x3 MC, then to manipulate the control equation for the purpose of making it suitable for controlling the 3x7 MC effectively, thus a good performance can be clearly seen according to the quality of the output voltage/current under typical R-L load, the shift between phases and the THD evaluation. The obtained simulation results which demonstrate the efficiency of the new control algorithm are presented and discussed

A new frequency analysis for diagnosis of bearing defects in induction motors using the adaptive lifting scheme of wavelet transforms

This work describes a novel and effective application of the adaptive wavelet transform for the detection of bearing faults on induction motor stator current. This transform is based on a three-step nonlinear lifting scheme: a fixed prediction followed by a space-varying update and a no additive prediction. This transformation technique is used in a diversity of applications in digital signal processing and the transmission or storage of sampled data (notably the compression of the sound, or physical measurements of accuracy). Many faults in induction motor have been identified as bearing defects, rotor defects and external defects. Experimental results confirm the utility and the effectiveness of the proposed method for outer raceway fault diagnosis under no load and full load conditions

Voltage sensorless based virtual flux control of three level NPC back-to-back converter dfigunder grid fault

In this paper, a harmonic elimination of grid and stator currents of doubly fed induction generator (DFIG) in case of grid fault without line voltage sensors is proposed . This can be achieved by compensating power based on virtual flux voltage sensorless technique. Direct power control with space vector modulation (DPC-SVM) is used to control both grid-side (GSC)and rotor-side converters (RSC). To achieve the control objective, compensated active and reactive powers are calculated based on virtual flux technique with balanced and harmonic free current as a control target. A theoretical analysis of active and reactive powers under unbalanced voltage source is clearly demonstrated and the effect of grid fault on the performance of DFIG is profoundly discussed. Simulation results verified the effectiveness of the modified control strategy

Optimal tilt angle for photovoltaic panels in the Algerian region of El-Oued in the spring season: An experimental study

The tendency to exploit solar energy in the electricity production in Algeria is a priority and a major goal of the Algerian government, and for this reason it seeks to provide all the necessary capabilities to achieve this lofty goal. Photovoltaic electricity is one of the effective technologies for the solar electricity production, but before installing any photovoltaic panel, it is important to determine its optimal tilt angle, and based on this, this study allowed to show the optimal tilt angle of the photovoltaic panels in the Algerian region of El Oued in the spring season, and accordingly, two days (March 21st, 2023, and April 21st, 2023) were chosen to conduct this experimental study. Based on the obtained results, the optimal PV tilt angle for the month of March is 33° and 28° for the month of April. In addition, the greater the amount of solar radiation, the higher the efficiency and productivity of the PV panels, as the highest values for them (6.31 % and 62.17 W, respectively) were recorded on April 21st, 2023. The results of this study will contribute to the correct installation of photovoltaic panels in the Algerian region of El-Oued, especially if the photovoltaic panels are equipped with dual-axis solar tracking systems

Continuous Nonlinear Model Predictive Current Control of PWM AC/DC Rectifier

The present work applies a nonlinear model predictive current control (NLMPCC) approach to ac/dc pulse width modulation (PWM) rectifier. A cascade structure is used to regulate Dc-link voltage and grid currents. The outer loop objective is to regulate the Dc-link voltage to the desired value, providing the level of the required active power to be used with the reactive power to calculate the referencing current for the inner loop. In the inner loop, the proposed approach is considered. After that, the nonlinear model of the converter is developed, based on continuous minimization of predicted tracking errors, the voltage at the terminal of the converter is deduced. After that, a PWM block is used to generate gate signals. Simulation results are performed to illustrate the efficiency of the proposed control la

Comparative Study of P&O and Fuzzy MPPT Controllers and Their Optimization Using PSO and GA to Improve Wind Energy System

Many academics have recently focused on wind energy installations. WECS (wind energy conversion system) is a renewable energy source that has seen significant development in recent years. Furthermore, compared to the use of power grid supply, the use of the WECS in the water pumping field is a cost-free option (economically). The purpose of this study is to demonstrate a wind-powered pumping mechanism. To obtain the best option, it considers and contrasts four distinct approaches. This research aims to improve the system\u27s performance and the quality of the generated power. The objective of the control of WECS with a permanent magnet synchronous generator (PMSG) is to carefully maximize power generation. Finally, this research employed the fuzzy logic control (FLC) and particle swarm optimization (PSO) algorithms improved using a genetic algorithm (GA). The proposed system\u27s performance was tested using the generated output voltage, current, and power waveforms, as well as the intermediate circuit voltage waveform and generator speed. The provided data show that the control technique used in this study was effective

growth of zno nanorods on fto glass substrate

n/

Elaboration and Characterization of ZnO/FTO thin films under different concentrations - Study dedicated to the photovoltaic systems - Study d

© 2020 IEEE. This paper presents an elaboration of thin films dedicated to photovoltaic systems. Zinc oxide (ZnO) on fluorine tin oxide (FTO) coated glass substrates are one of the best semiconductors oriented to solar cell preparations. In this study, the ZnO solution is performed with some sol concentration (0.1 M to 0.5 M) to verify its effect on thin-film samples. On the other hand, samples prepared are analyzed and characterized in structural and the optical properties using different techniques as ultraviolet-visible (UV-vis) spectrometry, Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD). This work showed the variation of the energy gap (Eg) values. The Eg values allow us to ensure good solar cells. In this study, the thin films prepared showed that the energy gap values are ranged between 3.29 eV and 3.4 eV. These results led us to confirm the possibility of having an easy passage of the electrical current. In addition, the transmittance spectra of the ZnO/FTO thin films showed an average of ~75% in the visible region and presented sharp absorption edges at 375 nm. The experimental preparation ensures a good decision about electrical energy production which based on the photovoltaic systems

Contribution au Diagnostic des Défauts dans les Machines Asynchrones : Comparaison entre l'Analyse Vibratoire et l'Analyse du Courant d'Alimentation

Il est impossible d'imaginer notre vie d'aujourd'hui sans machines électriques (tournantes), ces dernières qui ont un impact significatif pour la plupart des produits et des œuvres, d'être présentés dans de nombreux domaines. Le processus de la surveillance des machines tournantes menant à un bénéfice en temps et en argent, donc le processus de diagnostic a pour objectif de détecter les défauts d’une manière précoce, est devenu un impératif. Le diagnostic des défauts avant ses conversions à un dysfonctionnement s’effectue de diverses techniques, et le plus largement utilisé pratiquement, aujourd'hui, est la technique d'analyse des signaux vibratoires, car elle se base principalement sur l'analyse spectrale (FFT) des images de vibration. Cependant, les chercheurs, aujourd'hui, sont en concurrence et accélèrent afin de trouver un moyen plus efficace pour détecter les défauts dans les machines tournantes, et parmi ces techniques on cite, mais sans s'y limiter: l'analyse des signatures du courant statorique par la transformée de Fourier rapide (ASCS ou MCSA en Anglais) et l’analyse du même courant, mais par la transformée en ondelettes discrètes (ASCS-TOD ou MCSA-DWT en Anglais). L'objectif de cette étude est de faire une comparaison entre les méthodes d’analyses du courant : MCSA-FFT, MCSA-DWT et la méthode d’analyse vibratoire afin d'accéder à une décision précieuse. Cette étude a d'abord porté sur le développement d'un nouveau modèle dédié au défaut de roulement. Ce dernier nous a permis de faire la simulation numérique. Dans l'appréciation d’accomplir et justifier les résultats théorique, nous avons présenté des résultats expérimentaux pour faire la comparaison avec l’étude analytique (MCSA-FFT). Concernant la méthode de la MCSA-DWT, nous avons proposé un nouvel indicateur qui aide aux analyses des signaux d'une manière plus précise. Nous avons diagnostiqué le défaut de la cassure de barres, l’excentricité rotorique et le défaut de roulement par différentes techniques mentionnées plus haut, et aussi, notre étude pour différents défauts a été exploitée expérimentalemen

Comparative Study between Two Diagnostic Techniques Dedicated to the Mechanical Fault Detection in Induction Motors

Among the main causes which have a great influence on the service life of rotating electrical machines are mechanical faults. The squirrel cage induction motors are one of the most important induction motors in industrial and modern industrial applications. The reasons are the low cost, robustness, and low maintenance. In general fault causes unwanted vibrations in rotating machines and the rolling element bearing faults affect the induction machines with a significant percentage. It is a major problem among different faults because it can cause catastrophic damage. Early and accurate detection of rolling element bearing faults are essential for both effective fault management and fault isolation. This paper presents a detailed study of rolling element bearing faults in squirrel cage induction motors using two recent diagnostic techniques. The first technique uses the stator current signal based on the fast Fourier transform. According to this technique, it is carefully checked the spectral content of the stator current. The second technique uses the stray flux signature analysis. Experimental tests for different conditions as low load, full load operation, healthy and faulty states of the induction motors have been performed. So, a detailed comparison between the two techniques led us to achieve a judicious decision about the rolling element bearing faults detection